1. Field of the Invention
The present invention relates to obliquely inclined position determining mechanisms of cutting devices and in particular to mechanisms for determining obliquely inclined positions of saw units of cutting devices, which have rotary circular saw blades for cutting workpieces such as wooden workpieces, so that a type of cutting operation referred to as an “oblique cutting operation” can be performed with the saw units or the saw blades obliquely inclined relative to the workpieces. In this specification, “inclined position” is used to mean a position inclined in a right or left direction with respect to a cutting direction, unless otherwise noted.
2. Description of the Related Art
Japanese Laid-Open Patent Publication No. 8-252802, assigned to the same assignee as the present invention, teaches an obliquely inclined position determining mechanism that is operable to position a saw blade of a saw unit in a vertical position, where the saw blade extends substantially perpendicular to an upper surface of a table, and in obliquely inclined positions, where the saw blade may be inclined by an angle of 45° in the right and left directions with respect to the cutting direction relative to the upper surface of the table.
Japanese Laid-Open Patent Publication No. 2003-245901 teaches a mechanism that is operable to determine the positions of a saw blade of a saw unit in a vertical position and a 45° inclined position in one of the right and left directions. In addition, this mechanism is operable to determine a position of the saw blade in an additional position, such as a position inclined by an angle of 5° from the 45° inclined position.
However, the determinable inclined positions of the known mechanisms are limited to the frequently used vertical position and a 45° inclined position(s). Therefore, in order to set a saw unit or a saw blade in another position, such as a position between the vertical position and the 45° inclined position, the operator is required to perform the following operations. The operator first loosens a fixing lever, which otherwise fixes the inclined position of the saw unit, so that the saw unit can freely pivot about an axis. The operator then pivots the saw unit to the desired inclined position while observing the associated angular scale. Thereafter, with the saw unit held in the desired inclined position by the operator, the operator functions to tighten the fixing lever in order to fix the saw unit in the desired inclined position.
Still, in order to accurately fix the saw unit in the desired position, it is necessary for the operator to pivot the saw unit, which may be a relatively heavy unit, by small angles in one direction and an opposite direction while the operator repeatedly loosens and tightens the fixing lever. This adjusting operation may be very troublesome. Additionally, in practice it may be very difficult to acutely position the saw unit in the desired position.